Inductive position sensors

ABSTRACT

Methods and apparatuses to obtain increased performance and differentiation for an inductive position sensor through improvements to the sense element and target design are disclosed. In a particular embodiment, a sense element includes a transmit coil, a first receive coil that includes a first plurality of arrayed loops, wherein two or more of the first plurality of arrayed loops are at least one of phase blended and amplitude arrayed, and a second receive coil that includes a second plurality of arrayed loops, wherein two or more of the second plurality of arrayed loops are at least one of phase blended and amplitude arrayed, and wherein the first receive coil and the second receive coil are phase shifted. The sense element coils are arrayed in several geometries and layouts, and the coil and target geometry are manipulated to compensate for inherent errors in the fundamental design of an inductive position sensor.

BACKGROUND

Inductive position sensors provide feedback to the control systems forelectric motors. For synchronous motors, this feedback is required inorder to calculate the phase currents necessary to obtain the desiredtorque and achieve maximum motor efficiency.

Inductive position sensors operate on two core principles: induction ofelectromotive force (EMF) in a wire loop and induction of eddy currentsin conductive materials. EMF is induced by changing the magnetic fluxthrough a wire loop. This can be done by either changing the area of theloop within the magnetic field or by changing the strength of the field.Eddy currents are induced by either placing a conductor in a changingmagnetic field or by relative motion between a conductor and a magneticfield.

Inductive position sensors may result in inaccurate readings when thesignal strength in the sensing coil is weak or has a low signal to noiseratio. While multiple receive coils may be combined to produce astronger signal, this typically results in a larger form factor.Moreover, dead zones may occur in areas where signal traces intersect.Accordingly, there is a need to compensate for these drawbacks.

SUMMARY OF INVENTION

Embodiments in accordance with the present disclosure are directed to aninductive position sensor having phase blended, arrayed, multiloopinductive coils with layout compensated geometry. The phase blended,arrayed, multiloop inductive coils with layout compensated geometryincrease signal strength on receive coils of an inductive positionsensor, decrease the number of printed circuit board or printed filmlayers, provide the purest intended sinusoidal response signal foroptimal sensor performance, allow functionality and maintain signalquality in broad range of form factors and application requirements, anddecrease susceptibility to sensor and system variable's tolerance rangesand stacks. By increasing the signal strength in the receive coils, thesignal to noise ratio may be increased, thresholds for proper signalconditioning can be met, and sensor sensitivity to target position underall application conditions (e.g., airgap and temperature ranges) can beimproved.

Embodiments in accordance with the present disclosure increaseperformance and differentiation for an inductive position sensor, suchas those used in electric motor applications, through improvements tothe sense element and target design. The sense element coils are arrayedin several manners as described herein. Furthermore, the coil and targetgeometry are manipulated to compensate for inherent errors in thefundamental concept.

For inductive position sensing, the basic operating principles are usedby pairing a sensing element and a conductive target. Used inconjunction, the rotation of the target over the sensing elementsprovides output signals that can be captured with an applicationspecific integrated circuit (ASIC) and provided to, for example, avehicle electronic control unit (ECU).

An embodiment in accordance with the disclosure is directed to aninductive position sensor that includes a sense element having at leastone transmit coil, a first receive coil that includes a first pluralityof arrayed loops, wherein two or more of the first plurality of arrayedloops are phase blended, amplitude arrayed, or both, and a secondreceive coil that includes a second plurality of arrayed loops, whereintwo or more of the second plurality of arrayed loops are phase blended,amplitude arrayed, or both, and wherein the first receive coil and thesecond receive coil are phase shifted. The sensor also includes aconductive target and an integrated circuit configured to provide atransmission signal to the at least one transmit coil, provide a firstreference signal to the first receive coil, provide a second referencesignal to the second receive coil, and detect a position of the targetbased on change in the first reference signal and the second referencesignal.

In some embodiments, a particular loop in the first plurality of arrayedloops includes a first trace pattern in a first conductive layer, asecond trace pattern in a second conductive layer, and a plurality ofvias connecting the first trace pattern and the second trace pattern,and via pads corresponding to vias are located outside of an intendedsensing area of the particular loop. In some embodiments, a layout of atrace pattern for a particular loop is biased such that an edge of thetrace pattern adjacent an intended sensing area is used as a signalreference. In some embodiments, a trace pattern geometry for the firstplurality of arrayed loops and the second plurality particular loops iscompensated for a dead zone at an intersection of two loops.

In some embodiments, a particular loop in the first plurality of arrayedloops includes a first trace pattern in a first conductive layer, asecond trace pattern in a second conductive layer, and the firstconductive layer and the second conductive layer are composed ofconductive ink on printed film. In some embodiments, crossovers betweentrace segments in the first receive coil and the second receive coiloccur at natural transition points where conductor traces intersect. Insome embodiments, at least the first plurality of arrayed loops areasymmetric.

In some embodiments, the first receive coil and the second receive coilare arranged in a hanging coil layout. In these embodiments, the hangingcoil layout may be a grouped hanging coil layout. In these embodiments,the hanging coil layout may be an individually spaced hanging coillayout. In these embodiments, the hanging coil layout may be a splithanging coil layout. In some embodiments, the target is selected to beless than half an electrical period of the sensor.

Another embodiment in accordance with the present disclosure is directedto a sense element for an inductive position sensor, the sense elementincluding at least one transmit coil, a first receive coil that includesa first plurality of arrayed loops, wherein two or more of the firstplurality of arrayed loops are phase blended, amplitude arrayed, orboth, and a second receive coil that includes a second plurality ofarrayed loops, wherein two or more of the second plurality of arrayedloops are phase blended, amplitude arrayed, or both, and wherein thefirst receive coil and the second receive coil are phase shifted.

In some embodiments, a particular loop in the first plurality of arrayedloops includes a first trace pattern in a first conductive layer, asecond trace pattern in a second conductive layer, and a plurality ofvias connecting the first trace pattern and the second trace pattern,and via pads corresponding to vias are located outside of an intendedsensing area of the particular loop. In some embodiments, a layout of atrace pattern for a particular loop is biased such that an edge of thetrace pattern adjacent an intended sensing area is used as a signalreference. In some embodiments, a trace pattern geometry for the firstplurality of arrayed loops and the second plurality particular loops iscompensated for a dead zone at an intersection of two loops.

In some embodiments, a particular loop in the first plurality of arrayedloops includes a first trace pattern in a first conductive layer, asecond trace pattern in a second conductive layer, and the firstconductive layer and the second conductive layer are composed ofconductive ink on printed film. In some embodiments, crossovers betweentrace segments in the first receive coil and the second receive coiloccur at natural transition points where conductor traces intersect. Insome embodiments, at least the first plurality of arrayed loops areasymmetric.

In some embodiments, the first receive coil and the second receive coilare arranged in a hanging coil layout. In these embodiments, the hangingcoil layout may be a grouped hanging coil layout. In these embodiments,the hanging coil layout may be an individually spaced hanging coillayout. In these embodiments, the hanging coil layout may be a splithanging coil layout.

Another embodiment in accordance with the present disclosure is directedto a method for an inductive position sensor that includes providing asense element including at least one transmit coil, a first receive coilthat includes a first plurality of arrayed loops, wherein two or more ofthe first plurality of arrayed loops are phase blended, amplitudearrayed, or both, and a second receive coil that includes a secondplurality of arrayed loops, wherein two or more of the second pluralityof arrayed loops are phase blended, amplitude arrayed, or both, andwherein the first receive coil and the second receive coil are phaseshifted. The method also includes driving a transmission signal to theat least one transmit coil, detecting a first reference signal in thefirst receive coil, detecting a second reference signal to the secondreceive coil, placing a conductive target in proximity of the senseelement, and detecting a position of the target based on change in thefirst reference signal and the second reference signal.

The foregoing and other objects, features and advantages of theinvention will be apparent from the following more particulardescriptions of exemplary embodiments of the invention as illustrated inthe accompanying drawings wherein like reference numbers generallyrepresent like parts of exemplary embodiments of the invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example angularly arrayed receive coil layout inaccordance with an embodiment of the present disclosure;

FIG. 2 illustrates an example radially arrayed receive coil layout byfull coil width in accordance with an embodiment of the presentdisclosure;

FIG. 3 illustrates an example two signal, angularly and radiallyarrayed, receive coil layout in accordance with an embodiment of thepresent disclosure;

FIG. 4 illustrates an example X arrayed linear receive coil layout inaccordance with an embodiment of the present disclosure;

FIG. 5 illustrates an example X and Y arrayed linear receive coil layoutin accordance with an embodiment of the present disclosure;

FIG. 6A illustrates an example conductor layout for a first coil layerof a receive coil in accordance with an embodiment of the presentdisclosure;

FIG. 6B illustrates an example conductor layout for a second coil layerof the receive coil of FIG. 6B in accordance with an embodiment of thepresent disclosure;

FIG. 7A illustrates another example conductor layout in accordance withan embodiment of the present disclosure;

FIG. 7B illustrates a first layer of the coil layout of FIG. 7A inaccordance with an embodiment of the present disclosure.

FIG. 7C illustrates a second layer of the coil layout in accordance withan embodiment of the present disclosure.

FIG. 8 illustrates an example conductor layout in accordance with anembodiment of the present disclosure;

FIG. 9 illustrates an example of an ideal sinusoid;

FIG. 10 illustrates an example conductor trace using an ideal sinusoidmidline;

FIG. 11A illustrates an example compensated geometry for conductor tracecrossover in accordance with the present disclosure;

FIG. 11B illustrates the offset traces of FIG. 11A in accordance with anembodiment of the present disclosure.

FIG. 12 illustrates an example trace crossover to eliminate dead zonesin accordance with an embodiment of the present disclosure;

FIG. 13 illustrates an example coil layout and target starting positionfor a single coil sense element in accordance with embodiments of thepresent disclosure;

FIG. 14 illustrates an example coil layout and target starting positionfor a dual coil with 45° phase shift sense element in accordance withembodiments of the present disclosure;

FIG. 15 illustrates a plot of receive coil cross sectional width vsmechanical angle;

FIG. 16 illustrates a plot of error range (electrical angle) vs. coilwidth for an example inductive position sensor in accordance withembodiments of the present disclosure;

FIG. 17 illustrates a plot of error range (electrical angle) vs. tracewidth for an example inductive position sensor in accordance withembodiments of the present disclosure;

FIG. 18 illustrates crossover width variance with respect to coil widthfor an example inductive position sensor in accordance with embodimentsof the present disclosure;

FIG. 19 illustrates a plot of electrical angle vs. mechanical positionfor an example inductive position sensor in accordance with embodimentsof the present disclosure;

FIG. 20 illustrates an example trace pattern for a receive coil layoutin accordance with embodiments of the present disclosure;

FIG. 21A illustrates an example trace pattern for a first signal in theexample of FIG. 20 in accordance with embodiments of the presentdisclosure;

FIG. 21B illustrates an example trace pattern for a second signal in theexample of FIG. 20 in accordance with embodiments of the presentdisclosure;

FIG. 22 illustrates an example hanging coil layout in accordance withembodiments of the present disclosure;

FIG. 23 illustrates example grouped hanging coil layout in accordancewith embodiments of the present disclosure;

FIG. 24 illustrates example individually spaced hanging coil layout inaccordance with embodiments of the present disclosure;

FIG. 25 illustrates a hanging coil layout that is a grouped splithanging coil layout in accordance with embodiments of the presentdisclosure;

FIG. 26 illustrates a hanging coil layout that is an individually spacedsplit hanging coil layout in accordance with embodiments of the presentdisclosure;

FIG. 27A illustrates one pattern of the hanging coil layout of FIG. 26 ;

FIG. 27B illustrates another pattern of the hanging coil layout of FIG.26 ;

FIG. 28A illustrates an example symmetric coil pattern in accordancewith the present disclosure;

FIG. 28B illustrates an example loop shape of the symmetric coil patternof FIG. 28A;

FIG. 29A illustrates an example asymmetric coil pattern in accordancewith the present disclosure;

FIG. 29B illustrates an example loop shape of the asymmetric coilpattern of FIG. 29A;

FIG. 30 illustrates a symmetric loop shape and an asymmetric loop shapein accordance with the present disclosure on a linear scale; and

FIG. 31 sets forth a flow chart illustrating an example method for aninductive position sensor in accordance with the present disclosure.

DESCRIPTION OF EMBODIMENTS

The terminology used herein for the purpose of describing particularexamples is not intended to be limiting for further examples. Whenever asingular form such as “a”, “an” and “the” is used and using only asingle element is neither explicitly or implicitly defined as beingmandatory, further examples may also use plural elements to implementthe same functionality. Likewise, when a functionality is subsequentlydescribed as being implemented using multiple elements, further examplesmay implement the same functionality using a single element orprocessing entity. It will be further understood that the terms“comprises”, “comprising”, “includes” and/or “including”, when used,specify the presence of the stated features, integers, steps,operations, processes, acts, elements and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, processes, acts, elements, componentsand/or any group thereof.

It will be understood that when an element is referred to as being“connected” or “coupled” to another element, the elements may bedirectly connected or coupled via one or more intervening elements. Iftwo elements A and B are combined using an “or”, this is to beunderstood to disclose all possible combinations, i.e., only A, only B,as well as A and B. An alternative wording for the same combinations is“at least one of A and B”. The same applies for combinations of morethan two elements.

Accordingly, while further examples are capable of various modificationsand alternative forms, some particular examples thereof are shown in thefigures and will subsequently be described in detail. However, thisdetailed description does not limit further examples to the particularforms described. Further examples may cover all modifications,equivalents, and alternatives falling within the scope of thedisclosure. Like numbers refer to like or similar elements throughoutthe description of the figures, which may be implemented identically orin modified form when compared to one another while providing for thesame or a similar functionality.

In embodiments in accordance with the present disclosure, an inductiveposition sensor in a sensing element has output signals that are twophase shifted sinusoidal signals which allow for a ratiometricmeasurement in order to track angular position by taking the arctan. Thesensing element, which is directly connected to an integrated circuit(e.g., an application specific integrated circuit (ASIC)) includes atransmit coil and two receive coils. The transmit coil generates amagnetic field that is received by the receive coils. Driven by theintegrated circuit, and in parallel with a capacitor, the transmit coilacts as a LC oscillator circuit. The LC oscillator generates a magneticfield that is the transmitted signal to the receive coils. The polarityof the magnetic field is determined by the direction of the current inthe loop. The two receive coils are wire loops, connected to theintegrated circuit, that exist within the oscillating magnetic fieldgenerated by the transmit coil. The field induces current flow in thecoils and an EMF proportional to the area of the magnetic field withineach of the wire loops.

In some embodiments, the design of each receive coil creates multiplewire loops in the coil that have opposing EMF generation. Without thetarget present, the summation of the EMF for a given receive coil isdesigned to be zero volts. This voltage signal is the input to theintegrated circuit. Each coil is designed with a specified target toprovide a sinusoidal change in voltage as the target moves from onepoint over the position sensor to another. In some embodiments, thetarget is a conductive material that interacts with the magnetic fieldgenerated by the transmit coil. When placed above the coil, the fieldinduces eddy currents within the conductive target. The eddy currentsthen generate a second magnetic field which, according to Lenz's Law,opposes the initial magnetic field that interacted with the target. Theresult is an attenuated magnetic field in the area below (near) thetarget. The sensing element and the conductive target together generatea position signal. With the target present over a given wire loop, theattenuated magnetic field results in a change in the EMF generation forthe effected loop. The delta is used to track the position of thetarget. To accomplish this, the two receive coils are identical andphase shifted by 90°. This results in a sine and a cosine output ofwhich the arctan can be taken to calculate the position of the target.

In embodiments in accordance with the present disclosure, arrayed coilloops (e.g., phase blended, multiloop) may be implemented on eitherlinear (X,Y,Z) or angular (θ,R,Z) sensors. When connected in series,receive coils arrayed in the Y (linear) dimension or the R (radial)dimension result in summed sinusoids that are phase aligned to generatea sinusoid of greater amplitude. Multiple coil loop sets that are offsetin the Y (linear) dimension or the R (radial) dimension gain the benefitof each individual coil having greater field uniformity to provide acleaner signal. Receive coil loop sets arrayed in the X (linear)dimension or the θ (angular) dimension result in summed sinusoids thatare phase blended to the mean position of each of the coils with agreater amplitude. Coils may be arrayed in the X or θ dimensions by afull electrical period, however the phase blended coils are arrayed byless than a full electrical cycle with the optimal phase separationvalues being dependent on the number of receive coils and signaltransform method (i.e., 2 or 3 phase sinusoids). In various embodiments,angular sensors may be implemented as 360° sensors or arc sensors. Asused herein, “phase blended” may refer to angularly arrayed coil loopsets in 360° sensors or arc sensors, or X-arrayed coil loop sets in alinear sensor. As used herein, “amplitude arrayed” may refer to radiallyarrayed coil loop sets in 360° sensors or arc sensors, or Y-arrayed coilloop sets in a linear sensor.

Exemplary apparatuses and methods for an inductive position sensor inaccordance with the present disclosure are described with reference tothe accompanying drawings, beginning with FIG. 1 . FIG. 1 illustrates anexample coil layout of a single receive coil (100) of position sensorthat is angularly arrayed (i.e., θ arrayed) in accordance with thepresent disclosure. In the example of FIG. 1 , the receive coil (100)includes a first set of sinusoidal loops having a first sinusoidal tracepattern (101) (e.g., a sine wave) and a second sinusoidal trace pattern(103) that is the reflection of the first sinusoidal trace pattern(101). In some embodiments, sinusoidal trace patterns (101, 103) areformed on same plane (i.e., conductive layer) or different planes of asense element (120) (e.g., a multilayered PCB or printed filmstructure). In some embodiments, portions of each sinusoidal tracepattern (101, 103) are formed on one plane while other portions of eachsinusoidal trace patterns (101, 103) are formed on a different plane.The sinusoidal trace patterns (101, 103) define coil loops surroundingan intended sensing areas (105) for detecting a magnetic fieldattenuated by the target when the target is over an intended sensingarea (105). When the target is present over the intended sensing area(105), the attenuated magnetic field creates a change in the EMFgeneration of the affected loop, which is detectable from the signal onthe sinusoidal trace patterns (101, 103).

In the example of FIG. 1 , the receive coil (100) also includes a secondset of sinusoidal loops having a first phase-shifted sinusoidal tracepattern (107) and a second phase-shifted sinusoidal trace pattern (109)that is the reflection of the first phase-shifted sinusoidal tracepattern (107), where the phase-shifted sinusoidal trace patterns (107,109) are phase-shifted relative to the sinusoidal trace patterns (101,103). In some embodiments, phase-shifted sinusoidal trace patterns (107,109) are formed on same plane (i.e., conductive layer) or differentplanes of the sense element (120). In some embodiments, portions of eachphase-shifted sinusoidal trace pattern (107, 109) are formed on oneplane while other portions of each phase-shifted sinusoidal tracepatterns (107, 109) are formed on a different plane. The sinusoidaltrace patterns (107, 109) define coil loops surrounding an intendedsensing areas (111) for detecting a magnetic field attenuated by thetarget when the target is over an intended sensing area (111). When thetarget is present over the intended sensing area (111), the attenuatedmagnetic field creates a change in the EMF generation of the affectedloop, which is detectable from the signal on the sinusoidal tracepatterns (107, 109). By summing the measured EMF generation in theintended sensing areas (105, 111) and correlating the summed measurementto a mean position of the intended sensing areas, an enhanced positionsignal for the location of the target with respect to the sense element(120) is generated. The enhanced position signal has double theamplitude of a signal derived from a single sense area.

For further explanation, FIG. 2 illustrates an example coil layout of asingle receive coil (200) of an angular sensor that is phase arrayed(angularly arrayed) and radially arrayed (i.e., R arrayed) in accordancewith some embodiments of the present disclosure. In the example of FIG.2 , the receive coil (200) includes an angularly arrayed coil that isradially arrayed three times with coil patterns (201, 202, 203) andconnected in series. In this example, each coil pattern (201, 202, 203),like the receive coil (100) in FIG. 1 , includes a first set ofsinusoidal loops having a first sinusoidal trace pattern (e.g., a sinewave) and a second sinusoidal trace pattern that is the reflection ofthe first sinusoidal trace pattern, as well as a second set ofsinusoidal loops having a first phase-shifted sinusoidal trace patternand a second phase-shifted sinusoidal trace pattern that is thereflection of the first phase-shifted sinusoidal trace pattern, wherethe phase-shifted sinusoidal trace patterns are phase-shifted relativeto the sinusoidal trace patterns. Each aligned loop of the coils (201,202, 203) are connected by trace segments (212, 214). As the coils areconnected in series, the three coils are driven by the same signaloutput from an integrated circuit. As a result, an enhanced positionsignal for the location of the target with respect to the sense element(220) can be generated by summing the sinusoids of phase aligned loops,summing the sinusoids that are phase blended, and correlating theresulting sum to a mean position of the phase blended loops.

In some embodiments, portions of each sinusoidal trace pattern in eachcoil are formed on one plane while other portions of that sinusoidaltrace pattern are formed on a different plane such as top and bottomlayers of a PCB or various layers of a multilayer PCB. In some examples,an inner ring of vias (215) and an outer ring of vias (216) allow asignal to propagate between layers. Vias (217) may be used forcrossovers between positive and negative windings, and vias (218) may beused for crossovers between phase windings.

For further explanation, FIG. 3 illustrates an example two signal (e.g.,sine and cosine) angularly arrayed and radially arrayed receive coillayout (300) in accordance with some embodiments of the presentdisclosure. The receive coil layout includes three dual coil patterns(301, 302, 303) that are radially arrayed. Each dual coil pattern (301,302, 303) includes a first angularly arrayed coil corresponding to afirst signal (e.g., sine) and a second angularly arrayed coilcorresponding to a second signal (e.g., cosine). Each angularly arrayedcoil includes a first set of sinusoidal loops and a second set ofsinusoidal loops that are phase-shifted with respect to the first set ofsinusoidal loops. Because the first angularly arrayed coil and thesecond angularly arrayed coil are phase-shifted with respect to eachother (e.g., 90°, the resulting coil pattern includes two sets of phaseblended loops. The first angularly arrayed coils corresponding the firstsignal in each dual coil pattern (301, 302, 303) are connected in seriesto form a first receive coil. Phase-aligned loops in the first angularlyarrayed coils of each dual coil pattern are amplitude summed. Phaseblended loops in the first receive coil are summed and correlated to themean position of the loops. The second angularly arrayed coilscorresponding the second signal in each dual coil pattern (301, 302,303) are connected in series to form a second receive coil.Phase-aligned loops in the second angularly arrayed coils of each dualcoil pattern are amplitude summed. Phase blended loops in the secondreceive coil are summed and correlated to the mean position of theloops.

In some embodiments, portions of each sinusoidal trace pattern in eachreceive coil are formed on one plane while other portions of thatsinusoidal trace pattern are formed on a different plan, for example,where different planes are top and bottom layers of a PCB or variouslayers of a multilayer PCB. In some examples, an inner ring of vias(315) and an outer ring of vias (316) allow a signal to propagatebetween layers. Vias (317) may be used for crossovers between positiveand negative windings, and vias (318) may be used for crossovers betweenphase windings.

For further explanation, FIG. 4 illustrates an example X arrayed linearreceive coil layout (400) in accordance with some embodiments of thepresent disclosure. The example receive coil layout (400) shows a singlereceive coil that includes a first set of sinusoidal loops having afirst sinusoidal trace pattern (401) (e.g., a sine wave) and a secondsinusoidal trace pattern (403) that is the reflection of the firstsinusoidal trace pattern (401). The receive coil layout (400) alsoincludes a second set of sinusoidal loops having a first phase-shiftedsinusoidal trace pattern (407) and a second phase-shifted sinusoidaltrace pattern (409) that is the reflection of the first phase-shiftedsinusoidal trace pattern (407) (both shown in dashed lines for clarity),where the phase-shifted sinusoidal trace patterns (407, 409) arephase-shifted relative to the sinusoidal trace patterns (401, 403).

For further explanation, FIG. 5 illustrates an example X and Y arrayedlinear receive coil layout (500) in accordance with some embodiments ofthe present disclosure. The example receive coil layout (500) shows asingle receive coil that includes a first set (501) of loops formed froma sinusoidal trace pattern (e.g., a sine wave) and its reflection. Thereceive coil layout (500) also includes a second set (503) of loops thatare phase-shifted relative to the first set (501) of loops. The receivecoil layout (500) also includes a third set (505) of loops formed fromanother sinusoidal trace pattern (e.g., a sine wave) and its reflection.The receive coil layout (500) also includes a fourth set (507) of loopsthat are phase-shifted relative to the third set (505) of loops. Thefirst and second set of sinusoidal loops are Y-arrayed with respect tothe third and fourth set of sinusoidal loops (shown in dashed lines forclarity).

For further explanation, FIG. 6A illustrates a coil layout (600) for atop layer of a dual coil pattern for two receive coils corresponding todistinct signal patterns (e.g., sine and cosine) and FIG. 6B illustratesa coil layout (650) for a bottom layer of a dual coil pattern for tworeceive coils corresponding to the distinct signal patterns, inaccordance with some embodiments of the present disclosure. For example,the coil layout (600) may be disposed on a top layer of a PCB and coillayout (650) may be disposed on a bottom layer of the PCB. The coillayout (600) includes a transmit signal input line (681) and a transmitcoil (680) that loops around a dual receive coil layout described below.

In FIG. 6A, the coil layout (600) includes a first receive signal coilpattern that is angularly arrayed and a second receive coil that is alsoangularly arrayed, where the first receive coil and the second receivesignal coil pattern are themselves angularly arrayed with respect toeach other. The coil layout (600) includes sets of trace segments thatcorrespond to portions of sinusoidal patterns. In the example of FIG.6A, trace segment (601) corresponds to a portion of a first sinusoidalpattern (e.g., sine) of the first signal, trace segment (603)corresponds to a portion of a first sinusoidal pattern (e.g., cosine) ofthe second signal, trace segment (602) corresponds to a portion of asecond sinusoidal pattern (e.g., phase-shifted sine) of the first signalthat is phase-shifted with respect to the first sinusoidal pattern ofthe first signal, and trace segment (604) corresponds to a portion of asecond sinusoidal pattern (e.g., phase-shifted cosine) of the secondsignal that is phase-shifted with respect to the first sinusoidalpattern of the second signal. The adjacent set of trace segments (605,606, 607, 608) follow a reverse direction of the signal patternsrespectively corresponding to trace segments (601, 602, 603, 604).Forward direction sets of trace segments (601, 602, 603, 604) alternatewith reverse direction sets of trace segments (605, 606, 607, 608)around the sensor in that in that each sinusoidal pattern loops aroundthe sensor before reversing direction to form a reflection of theforward direction pattern. Each sinusoidal pattern reverses direction ata natural junction point (e.g., where the current in the signalreverses). In the example, of FIG. 6A, the sinusoidal patterns (e.g.,sine, cosine, phase-shifted sine, phase-shift cosine) reverse directionat via pairs (630). Similarly, initial signal patterns (e.g., sine andcosine) transition to phase-shifted signal patterns (e.g., phase-shiftsine and phase-shifted cosine) at via pairs (640).

Trace segments in the coil layout (600) of FIG. 6A connect to tracesegments in the coil layout (650) of FIG. 6B through vias (610) betweenthe top layer in FIG. 6A and the bottom layer in FIG. 6B. To minimizecrossovers between signals and phases of signals, trace segmentscorresponding to portions of the sinusoidal pattern with increasingamplitude are disposed on one layer and trace segments corresponding toportions of the sinusoidal pattern with decreasing amplitude aredisposed on a different layer, with pass through vias connecting theincreasing portions to the decreasing portions. For example, tracesegments (601, 602, 603, 604) in FIG. 6A connect to trace segments (611,612, 613, 614) in FIG. 6B and trace segments (605, 606, 607, 608) inFIG. 6A connect to trace segments (615, 616, 617, 618) in FIG. 6B.

In the example coil layout (650) of FIG. 6B, like the example coillayout (600) of FIG. 6A, trace segment (611) corresponds to a portion ofa first sinusoidal pattern (e.g., sine) of the first signal, tracesegment (613) corresponds to a portion of a first sinusoidal pattern(e.g., cosine) of the second signal, trace segment (612) corresponds toa portion of a second sinusoidal pattern (e.g., phase-shifted sine) ofthe first signal that is phase-shifted with respect to the firstsinusoidal pattern of the first signal, and trace segment (614)corresponds to a portion of a second sinusoidal pattern (e.g.,phase-shifted cosine) of the second signal that is phase-shifted withrespect to the first sinusoidal pattern of the second signal. Theadjacent set of trace segments (615, 616, 617, 618) follow a reversedirection of the signal patterns respectively corresponding to tracesegments (611, 612, 613, 614). Forward direction sets of trace segments(611, 612, 613, 614) alternate with reverse direction sets of tracesegments (615, 616, 617, 618) around the sensor in that in that eachsinusoidal pattern loops around the sensor before reversing direction toform a reflection of the forward direction pattern. Each sinusoidalpattern reverses direction at a natural junction point (e.g., zeroamplitude). In the example, of FIG. 6B, the sinusoidal patterns (e.g.,sine, cosine, phase-shifted sine, phase-shift cosine) reverse directionat via pairs (631). Similarly, initial signal patterns (e.g., sine andcosine) transition to phase-shifted signal patterns (e.g., phase-shiftsine and phase-shifted cosine) at via pairs (641).

In the example of FIG. 6B, the coil layout (650) also includes the inputand output lines (685, 686) for the first receive coil, the input andoutput lines (687, 688) for the second receive coil, and the output linefor the transmit coil (680). When superimposed, trace segments in coillayout (600) of FIG. 6A and trace segments in coil layout (650) in FIG.6B form four sinusoidal patterns that loop around the sensor for a twosignal sense element. In such a configuration, two phases of each signalare blended to improve the signal to noise ratio (SNR). The arctan ofthe sine and cosine receive signals may be calculated to determine theposition of a target over the sense element.

For further explanation, FIG. 7A illustrates an example coil layout(700) for an arc sensor, FIG. 7B illustrates a first layer (710) of thecoil layout (700), and FIG. 7C illustrates a second layer (720) of thecoil layout (700), in accordance with some embodiments of the presentdisclosure. In some examples, the first layer (710) is formed on a toplayer of a sense element PCB and the second layer is formed on thebottom layer of the PCB. The coil layout (700) includes three radiallyarrayed coil patterns (701, 702, 703) that are connected in series. Eachcoil pattern includes two signal patterns (704, 705) corresponding totwo signals (e.g., sine and cosine). Each signal pattern isangularly-arrayed with three replicates. Trace segments (706) for thesignal patterns on one layer (710) convey the signal in opposingdirections (i.e., outward vs. inward or increasing vs. decreasing) onthe other layer (720). Vias (707) are used to pass a signal from thefirst layer (710) to the second layer (720) forming a signal pattern onfirst layer (710) and a reflection of the signal pattern on the secondlayer (720) to create a sinusoidal signal pattern.

In some embodiments in accordance with the present disclosure, coilloops may also be arrayed in the Z axis, which is normal to the plane ofthe transmit coil. Coil loops may be arrayed in the Z axis by stackinglayers of the medium used for placing the conductors if the conductingsegments are isolated from one another by an insulating layer. By way ofexample and not limitation, stacking coil loops may be carried out byusing multilayer PCBs with offset via positioning, multilayer PCBs withhidden vias on alternating layers, or by using conductive ink on printedfilm with printed insulation layers between crossover segments.Minimizing the thickness of the overall coil stack ensures a moreuniform magnetic field throughout the thickness. In some embodiments,the use of conductive ink on printed film minimizes the thickness of thestack and therefore provides the most optimal magnetic field.

For further explanation, FIG. 8 illustrates a detailed view of anexample layer of a coil layout (800) in accordance with some embodimentsof the present disclosure. The coil layout (800) is biased such that theedge, not the centerline, of the conductive trace (809) adjacent to theintended sensing area (805) is the reference used to generate the signaloutput. In other words, the edges of the conductive traces align withthe sinusoidal signal that defines the sensing area rather than thecenter of the conductive traces aligning the sinusoidal signal.

Using ideal sinusoidal geometry to generate PCB traces, if notconsidering the trace width of the conductor material, will result in aperfect sinusoidal response as the target travels over the coil loopsfrom the positive loop to the negative loop, as shown by the exampleideal sinusoidal geometry (900) depicted in FIG. 9 . In the example ofFIG. 9 , it is assumed that current flowing in a clockwise directioncreates a positive loop and current flowing in a counterclockwisedirection creates a negative loop. When a sinusoidal signal in a firstloop crosses the midline into the adjacent second loop, the currentwithin the second loop flows in a reverse direction with respect to thefirst loop. When including the PCB conductor trace width, the positiveand negative loops are disjointed, as shown by the conductor tracelayout (1001) depicted in FIG. 10 . This creates a dead zone at thetransition point between the loops that disrupts the sinusoidal outputthat is desired from the target traveling over the coil resulting inresidual errors in the signal. In some embodiments, the traces areoffset outward by width of the trace to reduce the amount of errorresulting from a dead zone, as shown in the compensated geometry (1100)FIG. 11A. FIG. 11B illustrates the offset traces of FIG. 11A where afirst portion (1102) of the geometry (1100) is implemented on one layerof a PCB and a second portion (1104) of the geometry (1100) isimplemented on another layer of the PCB. In other embodiments, a deadzone may be substantially eliminated using the crossover geometry (1200)depicted in FIG. 12 . Additionally, as previously discussed crossoversbetween loops and coil sets occur at natural transition points whereconductor trace segments intersect, as to not introduce any unintendedchanges to the sensing area and resulting output signal.

The geometry of the target is also selected to improve the intendedsignal output. FIG. 13 illustrates an exemplary coil layout (1301) andtarget (1303) starting position for a single receive coil sense elementin accordance with some embodiments of the present disclosure. FIG. 14illustrates an exemplary coil layout (1401) and target (1403) startingposition for a dual receive coil with 45° phase shift sense element inaccordance with some embodiments of the present disclosure. As shown inFIGS. 13 and 14 , ensuring that the target (1303, 1403) overhangs thereceive coils (1311, 1411, 1412) and transmit coils (1307, 1407)improves the output of the sensor. Additionally, the width of a targetis conventionally equal to the width of half an electrical period.Whereas, in embodiments in accordance with the present disclosure, thewidth of the target is selected to be slightly less than half anelectrical period to improve robustness against positional offsets.However, when considering the previously described minimization orelimination of dead zones as well as phase shifted coil sets, the targetwidth may be chosen in a manner to minimize the number of dead zonesthat it will interact with at any given time. For a single coil designthis will be smaller than half an electrical cycle by at least thedistance covered by a dead zone such that the target cannot be over twodead zones at the same time.

FIG. 15 illustrates a plot of receive coil cross sectional width vs.mechanical angle of an example inductive position sensor in accordancewith the present disclosure. Plotting the cross sectional width of thecoil loops vs. angular position shows four extended zones per electricalcycle that have zero coil width. These dead zones align with where thecoil transitions from a positive to a negative loop due to trace widthoverlap. While the target transitions over these locations, there willbe zero change in effected area in one of the receive coils, whereas theother receive coil will be changing at its peak change rate.

FIG. 16 illustrates a plot of error range (electrical angle) vs. coilwidth of an example inductive position sensor in accordance with thepresent disclosure. FIG. 17 illustrates a plot of error range(electrical angle) vs. trace width for a four pole pair 360 degreedesign of an example inductive position sensor in accordance with thepresent disclosure. It can be seen from FIGS. 16 and 17 that the deadzones are dependent on trace and receive coil width. FIG. 18 illustratesthat a 15 mm coil (1801) width results in a 0.88 mm crossover region(1807), while a 5 mm coil (1803) width results in a 0.32 mm crossoverregion (1805).

As shown in FIG. 19 , a two pole pair dual coil design (in accordancewith embodiments of the present disclosure decreases the magnitude ofperiodic error. FIG. 19 illustrates a plot of electrical angle vs.mechanical position for a single receive coil, assessing area only(1901), a single receive coil, assessing area and B-field gradient with1 transmission coil loop (1907), dual receive coils, assessing area only(1903), and dual receive coils, assessing area and B-field gradient with1 transmission coil loop (1905).

To increase balance between receive coils and maintain equal inductancethe coil patterns should terminate at natural junctions in order to linkand close receive loops without requiring trace segments that do notnaturally occur within the sinusoidal pattern. In a standard coil thiscannot be fully accomplished, as shown in the coil layout (2100) of FIG.20 . With more than one receive coil, only one could ever close atnatural junction points. The additional receive coils would requireextra trace segments to bridge between end points in the coil pattern.In FIGS. 20A and 20B, the receive coils (2101, 2103) from FIG. 20 aresplit up to show the difference between a natural closed coil loop andbridged loop that requires extra trace segments to connect and close thecoil loop.

In some embodiments in accordance with the present disclosure, tofacilitate the use of only closed coils with natural termination, ahanging coil design employed. In these embodiments, a hanging coil hasdifferent receive signals physically offset from one another, thusoccupying slightly different angular ranges within a given sensor area.For example, a 12 pole pair sensor requires 30° angular space for a fullelectrical period to exist. As shown in FIG. 20 , in a typical inductiveposition sensor, all receive coils (2101, 2103) would exist only withinthat 30°.

For further explanation, FIG. 22 illustrates an example hanging coillayout (2200) in accordance with some embodiments of the presentdisclosure. In a hanging coil layout, the termination and reflectionpoints of one receive coil are offset from the termination andreflection points of another receive coil. That is, the terminationpoints of one receive coil hangs off one end of an area occupied by bothreceive coils, and the termination points of the other receive coilhangs off the other end of the area occupied by both receive coils. Forexample, in FIG. 22 , one receive coil (2201) occupies a 0° to 30° rangeand another coil (2203) occupies a 7.5° to 37.5° range. The hanging coilmethod provides additional utility for multiloop phase blended coilsthat have a higher trace density on a PCB. In some form factors it canbe difficult to use phase blended coils due to the lack of availablespace for vias connecting traces between layers. A hanging coil canallow for the vias for one of the receive coils to be outside of thephysical space that the other receive coil exists in, thus having lowertrace density and more room for the via placement. In some variations, ahanging coil layout may be grouped hanging coil layout such that thetermination points (and reflection points) of the angularly arrayedsignals in a particular receive coil are aligned (i.e., grouped) alongthe same angle, where grouping angle of one receive coil is offset bysome degrees with respect to the grouping angle of the another receivecoil. In some variations, a hanging coil layout may be an individuallyspaced hanging coil layout such that the termination points (andreflection points) of the angularly arrayed signals in a particularreceive coil are individually spaced apart by some degrees. In thesevariations, the area occupied by the individually spaced terminationpoints (and reflection points) of one first receive coil is offset froman area occupied by the spaced termination points of another receivecoil. In some variations, a hanging coil layout may be a split hangingcoil layout where termination points of a first set of angularly arrayedsignals are split from a second set of angularly arrayed signals byintervening termination points of another receive coil.

For further explanation, FIG. 23 illustrates an example grouped hangingcoil layout (2300) and FIG. 24 illustrates another example individuallyspaced hanging coil layout (2400) in accordance with some embodiments ofthe present disclosure. For phase blended multiloop coils there aredifferent ways to employ hanging coil layouts. In some examples, all ofthe loops for a particular receive coil (2301, 2303) are grouped andterminated together as shown in FIG. 23 . In the example of FIG. 23 ,each receive coil (2301, 2303) occupies a 30° angular range. Thetermination points of each loop of the receive coil (2301) are groupedsuch that the loops are terminated along the same angle, which is offsetby 7.5° from the angle of the grouped termination points of the receivecoil (2303). Thus, the receive coil (2301) “hangs” over the receive coil(2303) on the left side of the coil layout (2300), and the receive coil(2303) hangs over the receive coil (2301) on the right side of the coillayout (2300). In other examples, each individual loop of each receivecoil (2401, 2403) are spaced offset from one another as shown in FIG. 24. In the example of FIG. 24 , the termination point of each loop in thereceive coil (2401) is spaced 1.88° apart, and the termination point ofeach loop in the receive coil (2403) is spaced 1.88° apart. Each loop ofeach coil occupies a 30° angular range and each coil (2401, 2403)occupies a 37.5° angular range. The receive coil (2401) hangs over thereceive coil (2403) 7.5° on the left and the receive coil (2403) hangsover the receive coil (2401) 7.5° on the right with a total angularrange of the layout being 43.14°. Each provide different spacing optionsthat may be better or worse for different applications depending on thesize of the sensor, number of PCB layers, manufacturing capabilities,etc. The grouped hanging coils can occupy a smaller angular range thanthe individually spaced hanging coils, which in general makes it themore cost-effective solution. For example, in a 12 pole pair, four loop,sensor the grouped hanging coil layout (2300) will occupy a totalangular range of 37.5°, whereas the individually spaced hanging coillayout (2400) will occupy 43.14°. The individually spaced hanging coilmay provide better blending of signal from each loop for each signal andmake it more robust to positional offsets.

For further explanation, FIG. 25 illustrates another example hangingcoil layout (2500) that is a grouped split hanging coil layout inaccordance with some embodiments of the present disclosure. Hangingcoils can result in imbalances due to sensor and/or target positionaloffsets. To improve performance under these conditions a hanging coilcan be split to have one of the receive signals partially hang off ofboth ends of an arc sensor. In the example of FIG. 25 , a first receivecoil (shown in solid lines) is split such that a portion (2501) of thereceive coil occupying a 41.26° angular range overhangs a second receivecoil (2503) (shown in dashed lines) occupying a 30° angular range by5.63°. The second receive coil (2503) overhangs a second portion (2505)of the first receive coil by 4.69°. That is, in the example of FIG. 25 ,one receive coil (dashed lines) has have all four of its loops occupyinga 30° range, while the other receive coil (solid lines) has two of itsloops hanging from −5.63° to 25.3° and its other two hanging from 4.69°to 35.63°. This layout decreases the trace density enough in the areaswhere vias are required, but also provides additional coil balance bysplitting the receive coil that is at either end of the sensing region,which provides engagement with more target wings at once and offers someamount of balance for positional offsets. The grouped split hanging coillayout is suitable in coil designs that phase blend a positive number ofcoil loops.

For further explanation, FIG. 26 illustrates an example hanging coillayout (2700) that is an individually spaced split hanging coil layout,with each receive coil (2701, 2703) shown separately in FIGS. 27A and27B. In these examples, loops of the receive coil (2701) are split suchthat two loops of the receive coil (2701) overhang the receive coil(2703) on the left and two loops of the receive coil (2701) overhang thereceive coil (2703) on the right. The loops of the receive coil (2701)are individually spaced apart, and the loops of the receive coil (2703)are individually spaced apart. This creates four negative loops and fourpositive loops of the coil (2703) and four positive loops of the coil(2701) that are bounded by two negative loops of the coil (2701). Theseexamples use a single electrical period sensor, however the utility ofthis layout is not limited to only single electrical period coils.Hanging coil layouts can be employed on any arc sensor regardless of thenumber of electrical periods or poles.

In the above examples, vias are located at natural transition points ofline segments, and thus would typically be located at the midline of thecurves. In some applications, there are space constraints that will notallow for optimizing coil width and via placement. However, due to thesize of vias, the location of transition points must be at a certainminimum radial position on the board. To maintain this position andstill optimize coil loop area an asymmetric coil is employed.

FIG. 28A illustrates an example symmetric coil pattern (2801) inaccordance with the present disclosure. FIG. 28B illustrates an exampleloop shape (2803) of the symmetric coil pattern of FIG. 28A. Inapplications with high trace density it is possible to optimize coilarea and via placement by having asymmetric coil widths. An inductiveposition sensor may employ sinusoidal trace layouts to generate thesinusoidal response from the target. These layouts may be created byhaving a sinusoidal trace geometry and its reflection about the midlineof the sensing area. This creates a sinusoidal response that is twicethe amplitude of the base coil trace geometry. In designs that utilizenatural transition points for trace routing, the coil geometry definesthe via placements radial position. The greater the radial position, themore area that is available for via placement. With high trace densityit is important to have vias as far out radially as possible, but thisis limited if the ID is too small and the resulting transition pointsare moved inward.

For further explanation, FIG. 29A illustrates an example asymmetric coilpattern (2901) in accordance with the present disclosure. FIG. 29Billustrates an example loop shape (2903) of the asymmetric coil patternof FIG. 29A. To keep the transition points further out, the coil designcan use two different amplitudes to generate the coil geometry. Theresulting sinusoid then has an amplitude A=A1+A2. This allows for agreater overall coil width by having A2 greater than A1, but keep thevias located where they would have been with a smaller coil width andlarger midline radius. The resulting greater coil sense area increasethe signal amplitude of the sensor. FIG. 30 illustrates a symmetric loopshape (3003) and an asymmetric loop shape (3001) in accordance with thepresent disclosure on a linear scale.

For further explanation, FIG. 31 sets forth a flow char illustrating anexample method for an inductive position sensor in accordance with anembodiment of the present disclosure. The method of FIG. 31 includesproviding (3110) a sense element comprising at least one transmit coil;a first receive coil that includes a first plurality of arrayed loops,wherein two or more of the first plurality of arrayed loops are at leastone of phase blended and amplitude arrayed; and a second receive coilthat includes a second plurality of arrayed loops, wherein two or moreof the second plurality of arrayed loops are at least one of phaseblended and amplitude arrayed, and wherein the first receive coil andthe second receive coil are phase shifted. In some example, providing(3110) a sense element is carried out by providing an inductive positionsensor having an arrayed receive coil layout such as the receive coillayouts described with reference to FIGS. 1-5, 6A, 6B, 7A, 8, 13, 14,18, 22-26, 27A, 28A, and 29A.

The example method of FIG. 31 also includes driving (3120) the at leastone transmit coil. In some example, driving (3120) the at least onetransit coil includes driving the at least one transmit coil with asignal in parallel with a capacitor to generate a magnetic field that isthe transmitted signal to the receive coils.

The example method of FIG. 31 also includes detecting (3130) a firstreference signal in the first receive coil and detecting (3140) a secondreference signal in the second receive coil. In some examples, detecting(3130) a first reference signal in the first receive coil and detecting(3140) a second reference signal in the second receive coil is carriedout by an integrated circuit that detects the voltage in the firstreceive coil and the second receive coil induced by the magnetic fieldgenerated by the signal transmitted by the transmit coil.

The example method of FIG. 31 also includes determining (3150) aposition of a conductive target in proximity of the sense element basedon a change in the first reference signal and the second referencesignal. In some examples, determining (3150) a position of a conductivetarget in proximity of the sense element based on a change in the firstreference signal and the second reference signal is carried out by theintegrated circuit determining the action of the first reference signaland the second reference signal. When the sense element includes anangularly or linearly arrayed (X-arrayed) coil layout, a phase blendedfirst reference signal is summed and correlated to the mean position ofthe coil loops and a phase blended second reference signal is summed andcorrelated to the mean position of the coil loops. When the senseelement includes a radially or linearly arrayed (Y-arrayed) coil layout,phase aligned signals are amplitude summed.

In view of the explanations set forth above, readers will recognize thatthe benefits the phase blended, arrayed, multiloop inductive coils withlayout compensated geometry include increased signal strength on receivecoils of an inductive position sensor, providing the purest intendedsinusoidal response signal for optimal sensor performance, allowingfunctionality and maintain signal quality in broad range of form factorsand application requirements, and decreased susceptibility to sensor andsystem variable's tolerance ranges and stacks. By increasing the signalstrength in the receive coils, the signal to noise ratio may beincreased, thresholds for proper signal conditioning can be met, andsensor sensitivity to target position under all application conditions(e.g., airgap and temperature ranges) can be improved.

It will be understood from the foregoing description that modificationsand changes may be made in various embodiments of the present disclosurewithout departing from its true spirit. The descriptions in thisspecification are for purposes of illustration only and are not to beconstrued in a limiting sense. The scope of the present disclosure islimited only by the language of the following claims.

What is claimed is:
 1. An inductive position sensor comprising: a senseelement comprising: at least one transmit coil; a first receive coilthat includes a first plurality of arrayed loops having two or morearrayed loop sets, wherein the two or more arrayed loop sets are atleast one of phase arrayed and amplitude arrayed; and a second receivecoil that includes a second plurality of arrayed loops having two ormore arrayed loop sets, wherein the two or more arrayed loop sets are atleast one of phase arrayed and amplitude arrayed, and wherein the firstreceive coil and the second receive coil are phase shifted; a conductivetarget; and an integrated circuit configured to: provide a transmissionsignal to the at least one transmit coil; detect a first referencesignal in the first receive coil; detect a second reference signal inthe second receive coil; and detect a position of the conductive targetbased on change in the first reference signal and the second referencesignal.
 2. The sensor of claim 1, wherein a particular loop in the firstplurality of arrayed loops includes a first trace pattern in a firstconductive layer, a second trace pattern in a second conductive layer,and a plurality of vias connecting the first trace pattern and thesecond trace pattern; and wherein via pads corresponding to vias arelocated outside of an intended sensing area of the particular loop. 3.The sensor of claim 1, wherein a layout of a trace pattern for aparticular loop is biased such that an edge of the trace patternadjacent an intended sensing area is used as a signal reference.
 4. Thesensor of claim 1, wherein a trace pattern geometry for the firstplurality of arrayed loops and the second plurality of arrayed loops iscompensated for a dead zone at an intersection of two loops.
 5. Thesensor of claim 1, wherein a particular loop in the first plurality ofarrayed loops includes a first trace pattern in a first conductivelayer, a second trace pattern in a second conductive layer; and whereinthe first conductive layer and the second conductive layer are composedof conductive ink on printed film.
 6. The sensor of claim 1, whereincrossovers between trace segments in the first receive coil and thesecond receive coil occur at natural transition points where conductortraces intersect.
 7. The sensor of claim 1, wherein the two or morearrayed loop sets of the first receive coil includes a first set ofloops that is angularly arrayed with respect to a second set of loopsand a third set of loops that is radially arrayed with respect to thesecond set of loops.
 8. The sensor of claim 1 wherein the first receivecoil and the second receive coil are arranged in a hanging coil layout.9. The sensor of claim 8, wherein the hanging coil layout is a groupedhanging coil layout.
 10. The sensor of claim 8, wherein the hanging coillayout is an individually spaced hanging coil layout.
 11. The sensor ofclaim 8, wherein the hanging coil layout is a split hanging coil layout.12. The sensor of claim 1, wherein the target is selected to be lessthan half an electrical period of the sensor.
 13. A sense element for aninductive position sensor, the sense element comprising: at least onetransmit coil; a first receive coil that includes a first plurality ofarrayed loops having two or more arrayed loop sets, wherein the two ormore arrayed loop sets are at least one of phase arrayed and amplitudearrayed; and a second receive coil that includes a second plurality ofarrayed loops having two or more arrayed loop sets, wherein the two ormore arrayed loop sets are at least one of phase arrayed and amplitudearrayed, and wherein the first receive coil and the second receive coilare phase shifted.
 14. The sense element of claim 13, wherein aparticular loop in the first plurality of arrayed loops includes a firsttrace pattern in a first conductive layer, a second trace pattern in asecond conductive layer, and a plurality of vias connecting the firsttrace pattern and the second trace pattern; and wherein via padscorresponding to vias are located outside of an intended sensing area ofthe particular loop.
 15. The sense element of claim 13, wherein a layoutof a trace pattern for a particular loop is biased such that an edge ofthe trace pattern adjacent an intended sensing area is used as a signalreference.
 16. The sense element of claim 13, wherein a trace patterngeometry for the first plurality of arrayed loops and the secondplurality of arrayed loops is compensated for a dead zone at anintersection of two loops.
 17. The sense element of claim 13, wherein aparticular loop in the first plurality of arrayed loops includes a firsttrace pattern in a first conductive layer, a second trace pattern in asecond conductive layer; and wherein the first conductive layer and thesecond conductive layer are composed of conductive ink on printed film.18. The sense element of claim 13, wherein the first receive coil andthe second receive coil are arranged in a hanging coil layout.
 19. Amethod for an inductive position sensor, the method comprising:providing a sense element comprising: at least one transmit coil; afirst receive coil that includes a first plurality of arrayed loopshaving two or more arrayed loop sets, wherein the two or more arrayedloop sets are at least one of phase arrayed and amplitude arrayed; and asecond receive coil that includes a second plurality of arrayed loopshaving two or more arrayed loop sets, wherein the two or more arrayedloop sets are at least one of phase arrayed and amplitude arrayed, andwherein the first receive coil and the second receive coil are phaseshifted; driving, by an integrated circuit, a transmission signal to theat least one transmit coil; detecting, by the integrated circuit, afirst reference signal in the first receive coil; detecting, by theintegrated circuit, a second reference signal in the second receivecoil; and determining, by the integrated circuit, a position of aconductive target in proximity of the sense element based on a change inthe first reference signal and the second reference signal.
 20. Thesensor of claim 1, wherein a coil having phase arrayed loop setsincludes two or more loop sets that are angularly arrayed in a 360°sensor or arc sensor, or x-axis arrayed in a linear sensor; and a coilhaving amplitude arrayed loop sets includes two or more loop sets thatare radially arrayed in a 360° sensor or arc sensor, or y-axis arrayedin a linear sensor.